Washing soda is a chemical compound that's related to baking soda. It's great for laundry, it removes grease, oil, and stains, softens water, and even has a few applications in baking and cooking. Known scientifically as sodium carbonate, washing soda can be derived from certain plant ashes, can be made industrially through a process that involves salt and limestone, or it can be converted from baking soda through a heat process, which is the only realistic way to make it at home.

Bake the baking soda. Depending on how large a batch you're making, this could take anywhere from 30 minutes to two hours.[1] Stir every 15 minutes to speed up the conversion and ensure it happens in a uniform fashion.[2]

Know when the process is complete. As the baking soda converts to washing soda, it will become courser, grainier, and more matte. Also, washing soda doesn't clump up like baking soda does. Washing soda grains will be more like sand and will run through your fingers.[3]

Learn what baking soda is. Baking soda, which is also known as sodium bicarbonate and sodium hydrogen carbonate, is the chemical compound with the formula NaHCO3. It is used as a cleaner, a deodorizer, and it's used in baking, along with many other uses.

Learn what washing soda is. Washing soda, also known as sodium carbonate, is the chemical compound with the formula Na2CO3. Washing soda has a much higher pH level than baking soda, and is not safe to consume.

The chemical difference between washing and baking soda is that baking soda has a hydrogen atom that washing soda doesn't, and it's missing one of the sodium atoms.

Boost your laundry detergent. Add between a half-cup and a full cup (125 to 250 grams) of washing soda to your washing along with your regular detergent. Use a full cup for heavily soiled loads or if you have hard water. The grease fighting nature of washing soda will boost your regular detergent's ability to clean and remove dirt and grime.

Clean your dishes. You can make your own dishwasher detergent by combining two cups (500 grams) each of washing soda and borax in a glass or plastic container with a lid. Replace the lid and shake to mix. Use about two tablespoons (30 grams) per dishwasher load.[6]

Don't use this detergent on aluminum, as the high alkalinity can damage the metal.

Make an all-purpose cleaner. Combine one-half teaspoon of washing soda (2.5 grams), two teaspoons of borax (10 grams), and one-half teaspoon (2.5 ml) of liquid soap in a spray bottle. Add in two cups of warm water and agitate to mix.

Use this to clean floors, bathrooms, toilets and showers, kitchens, or anywhere else that's dirty or grimy.[7]

To make washing soda, start by covering the bottom of a baking dish with a layer of baking soda that's about 1/4 inch thick. Then, put the baking dish in the oven at 400 degrees Fahrenheit and stir it every 15 minutes until it becomes coarse and matte, which can take 30 minutes to 2 hours. You'll know the baking soda has turned into washing soda when it no longer clumps and the grains run through your fingers like sand.